1. Technical Field
The present disclosure relates to memories, and more particularly to semiconductor memory devices, memory systems including the same and methods of operating memory systems.
2. Discussion of Related Art
Semiconductor memory devices may be classified into non-volatile memory devices such as flash memory devices and volatile memory devices such as Dynamic Random Access Memories (DRAMs). High speed operation and cost efficiency of DRAMs make it possible for DRAMs to be used for computer system memories.
Electrical or magnetic interference inside a computer system can cause a single bit of a DRAM to spontaneously flip to the opposite state, resulting in a bit error. Further, when a specific address is intensively applied to the DRAM, data retention reliability of memory cells coupled to a word-line designated by the specific address may degrade.